X0306 4 2019-03-01 0 0001388658 iRhythm Technologies, Inc. IRTC 0001670676 Vort David A C/O IRHYTHM TECHNOLOGIES, INC. 650 TOWNSEND STREET, SUITE 500 SAN FRANCISCO CA 94103 0 1 0 0 EVP, Sales Common Stock 2019-03-01 4 F 0 1838 97.34 D 19839 D Common Stock 2019-03-04 4 M 0 5044 3.65 A 24883 D Common Stock 2019-03-04 4 S 0 5044 95.892 D 19839 D Employee Stock Option (right to buy) 3.65 2019-03-04 4 M 0 5044 0.00 D 2015-01-01 2024-02-04 Common Stock 5044 72960 D Represents shares that have been withheld by the Issuer to satisfy income tax withholding and remittance obligations in connection with the vesting and net settlement of restricted stock units previously reported. The option exercise and sale reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 27, 2018. This transaction was executed in multiple trades at prices ranging from $95.01 to $96.86. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Kristen Blumenthal, attorney in fact 2019-03-05